(a) Field
The present invention generally relates to a method and an apparatus for providing a multicast service and a method and an apparatus for allocating a multicast service resource in a terminal-to-terminal direct communication.
(b) Description of the Related Art
Recently, technologies for providing a direct communication between terminals on the same cell or neighboring cells are being developed in a wireless communication system. The terminal-to-terminal direct communication is called a device-to-device (D2D) communication. In the conventional wireless communication system, a communication between terminals is performed through an infrastructure such as a base station. The terminal-to-terminal direct communication is a communication scheme for directly transmitting or receiving data between the terminals without passing the infrastructure.
The terminal-to-terminal direct communication may be performed through an unlicensed band as in WiFi-Direct™ or Bluetooth™. Alternatively, terminal-to-terminal direct communication may be performed through a licensed band such as a cellular communication band. If the terminal-to-terminal direct communication is performed through the unlicensed band, it is difficult to provide the scheduled and controlled service and the performance can be rapidly deteriorated. Therefore, the terminal-to-terminal direct communication through the cellular communication band is being developed.
Particularly, the terminal-to-terminal direct communication can be used for a multicast service. In the multicast service, a plurality of users can simultaneously receive the service through one channel such that the resource can be efficiently used. The multicast service can be used for a broadcast service.
A base station should allocate resources for the multicast service in order to support the multicast service of the terminal-to-terminal direct communication in the conventional cellular communication. Therefore, the multicast service can be provided within only the coverage of one base station. As a result, a terminal that is near a base station for providing the multicast service but belongs to the other base station cannot receive the multicast service.